VideoTools/internal/ui/timeline.go

package ui

import (
	"image/color"
	"math"

	"fyne.io/fyne/v2"
	"fyne.io/fyne/v2/canvas"
	"fyne.io/fyne/v2/driver/desktop"
	"fyne.io/fyne/v2/widget"
)

// TimelineWidget shows video timeline with keyframe markers
type TimelineWidget struct {
	widget.BaseWidget

	duration  float64   // Total duration in seconds
	position  float64   // Current position in seconds
	keyframes []float64 // Keyframe timestamps in seconds
	inPoint   *float64  // In-point marker (for cuts)
	outPoint  *float64  // Out-point marker (for cuts)
	onChange  func(float64) // Callback when user seeks

	// Internal state
	dragging bool
	hovered  bool

	// Cached rendering objects
	renderer *timelineRenderer
}

// NewTimeline creates a new timeline widget
func NewTimeline(duration float64, onChange func(float64)) *TimelineWidget {
	t := &TimelineWidget{
		duration: duration,
		position: 0,
		onChange: onChange,
	}
	t.ExtendBaseWidget(t)
	return t
}

// SetDuration updates the timeline duration
func (t *TimelineWidget) SetDuration(duration float64) {
	t.duration = duration
	if t.renderer != nil {
		t.renderer.Refresh()
	}
}

// SetPosition updates the current playback position
func (t *TimelineWidget) SetPosition(position float64) {
	t.position = position
	if t.renderer != nil {
		t.renderer.Refresh()
	}
}

// SetKeyframes sets the keyframe timestamps
func (t *TimelineWidget) SetKeyframes(keyframes []float64) {
	t.keyframes = keyframes
	if t.renderer != nil {
		t.renderer.Refresh()
	}
}

// SetInPoint sets the in-point marker
func (t *TimelineWidget) SetInPoint(position *float64) {
	t.inPoint = position
	if t.renderer != nil {
		t.renderer.Refresh()
	}
}

// SetOutPoint sets the out-point marker
func (t *TimelineWidget) SetOutPoint(position *float64) {
	t.outPoint = position
	if t.renderer != nil {
		t.renderer.Refresh()
	}
}

// SetOnChange sets the callback function for position changes
func (t *TimelineWidget) SetOnChange(callback func(float64)) {
	t.onChange = callback
}

// CreateRenderer implements fyne.Widget
func (t *TimelineWidget) CreateRenderer() fyne.WidgetRenderer {
	t.renderer = &timelineRenderer{
		timeline: t,
	}
	t.renderer.refresh()
	return t.renderer
}

// Tapped handles tap events
func (t *TimelineWidget) Tapped(ev *fyne.PointEvent) {
	t.seekToPosition(ev.Position.X)
}

// TappedSecondary handles right-click (unused for now)
func (t *TimelineWidget) TappedSecondary(*fyne.PointEvent) {}

// Dragged handles drag events
func (t *TimelineWidget) Dragged(ev *fyne.DragEvent) {
	t.dragging = true
	t.seekToPosition(ev.Position.X)
}

// DragEnd handles drag end
func (t *TimelineWidget) DragEnd() {
	t.dragging = false
}

// MouseIn handles mouse enter
func (t *TimelineWidget) MouseIn(*desktop.MouseEvent) {
	t.hovered = true
}

// MouseOut handles mouse leave
func (t *TimelineWidget) MouseOut() {
	t.hovered = false
}

// MouseMoved handles mouse movement (unused for now)
func (t *TimelineWidget) MouseMoved(*desktop.MouseEvent) {}

// seekToPosition converts X coordinate to timeline position
func (t *TimelineWidget) seekToPosition(x float32) {
	if t.duration <= 0 || t.Size().Width <= 0 {
		return
	}

	// Calculate position from X coordinate
	ratio := float64(x) / float64(t.Size().Width)
	ratio = math.Max(0, math.Min(1, ratio)) // Clamp to [0, 1]
	position := ratio * t.duration

	t.position = position
	if t.onChange != nil {
		t.onChange(position)
	}

	if t.renderer != nil {
		t.renderer.Refresh()
	}
}

// MinSize returns the minimum size for the timeline
func (t *TimelineWidget) MinSize() fyne.Size {
	return fyne.NewSize(100, 30)
}

// timelineRenderer renders the timeline widget
type timelineRenderer struct {
	timeline *TimelineWidget

	// Canvas objects
	background      *canvas.Rectangle
	progressFill    *canvas.Rectangle
	keyframeLines   []*canvas.Line
	inPointLine     *canvas.Line
	outPointLine    *canvas.Line
	scrubberLine    *canvas.Line
	scrubberCircle  *canvas.Circle

	objects []fyne.CanvasObject
}

// Layout positions the timeline elements
func (r *timelineRenderer) Layout(size fyne.Size) {
	if r.background != nil {
		r.background.Resize(size)
	}

	r.refresh()
}

// MinSize returns the minimum size
func (r *timelineRenderer) MinSize() fyne.Size {
	return r.timeline.MinSize()
}

// Refresh updates the timeline display
func (r *timelineRenderer) Refresh() {
	r.refresh()
	canvas.Refresh(r.timeline)
}

// refresh rebuilds the timeline visuals
func (r *timelineRenderer) refresh() {
	t := r.timeline
	size := t.Size()

	if size.Width <= 0 || size.Height <= 0 {
		return
	}

	// Clear old objects
	r.objects = make([]fyne.CanvasObject, 0)

	// Background (dark gray)
	if r.background == nil {
		r.background = canvas.NewRectangle(color.NRGBA{R: 40, G: 40, B: 40, A: 255})
	}
	r.background.Resize(size)
	r.objects = append(r.objects, r.background)

	// Progress fill (lighter gray showing played portion)
	if t.duration > 0 {
		progressRatio := float32(t.position / t.duration)
		progressWidth := size.Width * progressRatio

		if r.progressFill == nil {
			r.progressFill = canvas.NewRectangle(color.NRGBA{R: 60, G: 60, B: 60, A: 255})
		}
		r.progressFill.Resize(fyne.NewSize(progressWidth, size.Height))
		r.progressFill.Move(fyne.NewPos(0, 0))
		r.objects = append(r.objects, r.progressFill)
	}

	// Keyframe markers (yellow vertical lines)
	if len(t.keyframes) > 0 && t.duration > 0 {
		r.keyframeLines = make([]*canvas.Line, 0, len(t.keyframes))
		keyframeColor := color.NRGBA{R: 255, G: 220, B: 0, A: 180} // Yellow with transparency

		for _, kfTime := range t.keyframes {
			ratio := float32(kfTime / t.duration)
			x := ratio * size.Width

			line := canvas.NewLine(keyframeColor)
			line.StrokeWidth = 1
			line.Position1 = fyne.NewPos(x, 0)
			line.Position2 = fyne.NewPos(x, size.Height)

			r.keyframeLines = append(r.keyframeLines, line)
			r.objects = append(r.objects, line)
		}
	}

	// In-point marker (blue vertical line)
	if t.inPoint != nil && t.duration > 0 {
		ratio := float32(*t.inPoint / t.duration)
		x := ratio * size.Width

		if r.inPointLine == nil {
			r.inPointLine = canvas.NewLine(color.NRGBA{R: 0, G: 120, B: 255, A: 255})
		}
		r.inPointLine.StrokeWidth = 2
		r.inPointLine.Position1 = fyne.NewPos(x, 0)
		r.inPointLine.Position2 = fyne.NewPos(x, size.Height)
		r.objects = append(r.objects, r.inPointLine)
	}

	// Out-point marker (red vertical line)
	if t.outPoint != nil && t.duration > 0 {
		ratio := float32(*t.outPoint / t.duration)
		x := ratio * size.Width

		if r.outPointLine == nil {
			r.outPointLine = canvas.NewLine(color.NRGBA{R: 255, G: 60, B: 60, A: 255})
		}
		r.outPointLine.StrokeWidth = 2
		r.outPointLine.Position1 = fyne.NewPos(x, 0)
		r.outPointLine.Position2 = fyne.NewPos(x, size.Height)
		r.objects = append(r.objects, r.outPointLine)
	}

	// Current position scrubber (white vertical line with circle on top)
	if t.duration > 0 {
		ratio := float32(t.position / t.duration)
		x := ratio * size.Width

		// Scrubber line
		if r.scrubberLine == nil {
			r.scrubberLine = canvas.NewLine(color.NRGBA{R: 255, G: 255, B: 255, A: 255})
		}
		r.scrubberLine.StrokeWidth = 2
		r.scrubberLine.Position1 = fyne.NewPos(x, 8)
		r.scrubberLine.Position2 = fyne.NewPos(x, size.Height)
		r.objects = append(r.objects, r.scrubberLine)

		// Scrubber circle (handle at top)
		if r.scrubberCircle == nil {
			r.scrubberCircle = canvas.NewCircle(color.NRGBA{R: 255, G: 255, B: 255, A: 255})
		}
		circleRadius := float32(6)
		r.scrubberCircle.Resize(fyne.NewSize(circleRadius*2, circleRadius*2))
		r.scrubberCircle.Move(fyne.NewPos(x-circleRadius, -circleRadius))
		r.objects = append(r.objects, r.scrubberCircle)
	}
}

// Objects returns all canvas objects for the timeline
func (r *timelineRenderer) Objects() []fyne.CanvasObject {
	return r.objects
}

// Destroy cleans up the renderer
func (r *timelineRenderer) Destroy() {}